Australia's government promises to push through a sweeping carbon emissions trading system despite a parliamentary defeat. The plan would require the country's biggest polluters to buy permits for emitting carbon dioxide. Government ministers want the legislation to be passed before United Nations climate change talks in December.

The Australian government has proposed what some say is the world's most ambitious carbon trading program. It would force the country's 1,000 worst polluters to buy carbon dioxide permits and would cover about 75 percent of emissions. The aim is to curb greenhouse gas pollution by between five and 25 percent by 2020.

The plan needs the approval of Australia's upper house of parliament, the Senate. A recent vote, however, saw the plan defeated by an unusual alliance of Greens, who think the program does not go far enough to protect the environment, and conservative lawmakers, who say it will damage industry and cost jobs.

Undeterred, Climate Change Minister Penny Wong says the government will try again to have the legislation passed.

"We will bring this bill back before the end of the year because we on this side understand we have to start the economic transformation we need. If we don't, this nation goes to Copenhagen with no means to deliver our targets. And if we don't, the message to Copenhagen would be that Australia is once again going backward on climate change," said Wong.

Conservative politicians think that Australian businesses, especially the dominant resources sector, will lose their competitive edge under the government's carbon trading program.

Federal opposition leader Malcolm Turnbull proposes a different plan that he says would help both the economy and the environment. However, he says the climate change minister rejected it.

"We put forward a report only a few days ago which showed some alternatives that would make for a scheme that was greener, cheaper and smarter. A greener, cheaper and smarter scheme and she just dismissed it out of hand and said it was a mongrel idea," he said.

There is hope that a compromise can be reached to allow the carbon trading mechanism to pass through the Senate.

The opposition and the government have struck a deal to approve the part of the climate legislation that sets renewable energy targets.

It means 20 percent of Australia's power supply must come from renewable sources by 2020. But there still is no agreement on the more contentious legislation covering carbon trading, which still divides Australia's parliament. If the political impasse continues it could trigger an early election.

The debate over emissions trading has prompted a flurry of research into how Australia, which relies heavily on coal to generate electricity, can reduce pollution.

The mining industry is spending vast amounts to find ways to produce coal that burns more cleanly.

James McGregor is a government scientist who says that storing carbon emissions deep underground is one way forward.

"What we do is when we compress the carbon dioxide at the back end of the capture plant we compress to what's known as a supercritical liquid. So a supercritical liquid is at room temperature. It has the density of a solid but it behaves like a liquid, so we can use standard pumping systems to move carbon dioxide around," he said.

Australia, one of the world's worst per capita emitters of greenhouse gases, also is pursuing a renewable energy options, including wind, solar, geothermal and tidal power.

Much of the debate has focused on Australia's vulnerability to climate change, which many scientists say is worsened by human emissions of greenhouse gases - mostly from burning coal and oil. Warmer temperatures are expected to change weather patterns, causing more droughts and floods in parts of the world.

But a former senior official of the World Bank thinks the needs of developing countries must be urgently considered.

David Freestone, who is visiting Australia, says that poorer economies feel the full force of a shifting climate.

"There's big floods in China, in India. You see in Africa the increased desertification now in the Sahelian regions, in the south of the Sahara," he said. "The incidents of droughts - and Australia knows this more than anyone I would imagine - the incidents of droughts has radically increased. Fifty percent of the Earth could be suffering droughts within the next 50 years."

In Australia, climate change skeptics say that warming temperatures are part of a natural cycle and are not influenced by man's use of fossils fuels. The majority of Australians disagree and want their political leaders to take a decisive stand against global warming that many believe has the potential to inflict more severe damage.